This invention relates to woodworking tools. Specifically, this invention relates to a variable cutting angle hand plane.
Hand planes have been used for hundreds of years to smooth the surface of wood. A hand plane works when a woodworker pushes or pulls the plane across the surface of the wood which allows the sharp blade of the plane iron to engage the wood and shear off a thin layer of wood, thereby smoothing the wood surface.
FIG. 1 shows an expanded view of a prior art hand plane. The hand plane assembly 10 has a base unit 12, in which the bottom of the base unit 12 is the sole 14. In addition, the base unit 12 has an opening in the sole 14 which is called the throat 16. Attached to the base unit 12 is at least one handle or tote 18. A device called a frog 20 extends upward from the inside of the base unit 12. The frog 20 rigidly screws to the base unit 12 with two mounting screws 21. The frog 20 holds the blade or cutter which is known as the iron 28 at a preset angle (approximately 45°) with respect to the sole 14.
The user can turn the depth adjuster 22 which allows the iron 28 to extend farther through the throat 16. Adjustment of the iron 28 depth allows the iron 28 to engage a deeper or shallower cut in the wood being planed. The lateral adjuster 24 allows the user to adjust the iron 28 into a left or right position. This in turn, allows for deeper cuts on one side of the plane or the other. A bolt inserted near the center of the frog 20 is called the fulcrum stud 26. This stud 26 allows the iron 28 to be fastened securely to the frog 20, so as to make a secure, tight fit which holds the iron 28 in place during use.
In order for the iron 28 to be of use, it must be sharpened. The sharpened area on an iron 28 is called the bevel 29. Most prior art hand planes are designed in one of two ways. They either have the iron bevel-up, or the bevel-down in relation to the sole 14 of the plane. Typically planes that have a down bevel are similar to the design shown in the hand plane assembly of FIG. 1. These planes are most common and generally best for planning along the grain of the surface being planed. On the other hand, common bevel-up irons are used in a different style of hand plane (not shown) which do not have the frog. Instead, the iron 28 lays on a fixed angle inclined surface on the inside of the base unit 12 without the aid of the frog 20. This allows a bevel-up iron 28 to lie at a much more reclined angle inside the base unit 12 of the plane.
A cap iron 30 is commonly used in conjunction with the iron 28 on bevel-down type planes. The cap iron 30 is secured to the iron 28 by the use of a cap iron screw 36. This cap iron 30 acts as a chip breaker which helps to curl the cuttings cut by the iron 28 before they have a chance to split away from the larger working piece of wood. The end result is that the chip breaker part 38 on forward end of the cap iron 30 as seen in FIG. 1, which is the rounded-out bottom portion of the cap iron 30, is desirable in bevel-down type irons 28. Overall, the chip breaker contributes for much smoother cutting on the work surface of the wood. The iron 28 and the cap iron 30 when bolted together by the use of the cap iron screw 36 become one piece, which is held onto the frog 20 by the use of the lever cap 32. This lever cap has a lever 34 with a cam on the end which applies pressure against the cap iron 30 to hold the cap iron 30 and the iron 28 assembly in place on top of the frog 20. The cam on the bottom of the lever 34 causes the lever cap 32 to pivot around the fulcrum stud 26 and remain tight on the cap iron 30 and iron 28 assembly.
A low angle bevel-up type iron plane which is not shown, is commonly known to one skilled in the art. A low angle iron allows a user with the much more reclined angle on the iron (approximately 37°) to use the plane in softer types of wood or the end grain of wood. The sharper attack angle allows the plane to cut harder woods or those with more difficult grain. Additionally, planes with a high cutting angle (approximately 90°), such as scraper planes (not shown), generally are used for scraping the top surface off the surface to be planed, such as scraping a finish or paint off the surface being planed. Thus, each type of plane, low angle, medium angle, or high angle scraper has its own specific purpose.
One problem in the prior art is that for every type of job, one needs separate hand planes to properly do the job. Therefore, it would be desirable to have one hand plane that can perform the jobs of multiple hand planes. Therefore, the primary feature or advantage of the current invention is to provide an improved variable cutting angle hand plane.
Another feature or advantage of the current invention is a hand plane suitable for using either bevel-up or bevel-down plane irons.
Another feature or advantage of the current invention is to provide a hand plane which can be used as a low angle plane, medium angle plane, and a high angle plane.
Another feature or advantage of the current invention is a hand plane which allows the throat to adjust for optimizing cutting.
A further feature or advantage is the provision of a variable cutting angle hand plane which is economical to manufacture, durable in use, and efficient in operation.
One or more of these and/or other features or advantages of the invention will be apparent from the specification and claims that follow.